Gale Warning 300, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
1100 AM AST WED NOV 21 2007

.SYNOPSIS...
MAJOR UPR LOW COMPLEX PERSISTS ROUGHLY ALG 170W WITH SGFNT COLD
AIR ALF. UPR RIDGE AT 500 MB REFORMING ALG 134W WHICH SETS UP STG
SOUTH FLOW ALF OVR THE CENTRAL GULF. 12Z NCEP SFC ANALYSIS SHOWS
985 MB IN BRISTOL BAY...FRONT ALG 148W...AND A DEVELOPING LOW
NEAR 49N 164W UNDER COLD AIR. AT 250 MB WESTERLY JET EXIT NEAR
38N 165W TO SUPPORT SFC DEVELOPER AND A BACKING FLOW TO 120KT ALG
150W OR SO. COLD CU OBVIOUS ON GOES-W IN SOUTHERN LOW.

.SHORT RANGE...THE CURRENT SATELLITE IMAGERY SHOWS THE PANHANDLE
UNDER MOSTLY CLOUDY SKIES WITH SOME SCATTERED SHOWERS MOVING OVER
THE AREA FROM THE WEST. THERE ARE SOME GUSTY WINDS OVER THE AREA
THIS MORNING BUT THEY SHOULD BE DIMINISHING THROUGH THE AFTERNOON
AS THE PRESSURE GRADIENT WEAKENS. THE STRONGEST WIND ATTM IS
OVER NORTHERN LYNN CANAL WITH GUSTS TO 35 MPH...THESE WINDS
SHOULD DECREASE THROUGH THE AFTERNOON BUT MAY STAY ON THE BREEZY
SIDE INTO THE EVENING HOURS.

THROUGH THURSDAY AFTERNOON WILL USE A BLEND OF THE 12Z GFS40 AND
UKMET AS WANTED TO TONE DOWN THE STRENGTH OF THE WAVE MOVING INTO
THE SW GULF THURSDAY. WITH THAT SAID...A UPPER RIDGE WILL BUILD
OVER THE AREA FROM THE WEST THROUGH THE AFTERNOON AND THE AXIS OF
THIS RIDGE WILL PROPAGATE TO THE EAST TO BE OVER BC THROUGH
THURSDAY. THIS RIDGE WILL CAP SOME OF THE SHOWERS OVER THE AREA
THIS EVENING BUT WITH THE ONSHORE FLOW AT ALL LEVELS THERE SOME
DRIZZLE MAY DEVELOP OVERNIGHT. WILL JUST KEEP A CHANCE OVER MOST
OF THE NORTHERN HALF OF THE PANHANDLE THROUGH TONIGHT EXCEPT FOR
ZONE 17 AS WITH A STRONG SOUTHERLY FLOW THINK LIGHT RAIN WILL
CONTINUE THROUGH TONIGHT. THE WINDS FOR TONIGHT WILL NOT BE THAT
STRONG WITH WINDS NO MORE THAN 20 MPH OUT OF THE EAST AS THE HIGH
IN BC WILL KEEP SOME HIGHER WINDS IN EXPOSED AREAS FROM THE
INTERIOR.

FOR THANKSGIVING DAY...A SURFACE WAVE WILL MOVE OUT OF THE NORTH
PACIFIC AND INTO THE SW GULF BY THE AFTERNOON. THERE IS GOOD
SOUTHERLY JET SUPPORT WITH THIS WAVE THAT MAY HELP WITH THE
DEVELOPMENT. THERE IS LARGE SPREADS IN THE ENSEMBLE MEMBERS WITH
THE STRENGTH OF THIS WAVE SO CONFIDENCE IN THIS FEATURE IS LOW TO
FAIR. THIS WAVE WILL INCREASE THE WINDS ACROSS THE CENTRAL AND
EASTERN GULF TO MAX GALES OVER THE OFFSHORE AND NORTHERN GULF AND
MIN GALES TO MAX SMALL CRAFT OVER THE EASTERN GULF BY THURSDAY
AFTERNOON. THERE MAY BE A SLIGHT BREAK IN THE RAIN FOR PAYA BUT
FOR THE MOST PART THEY WILL REMAIN ON THE WET SIDE WITH THE
STRONG ONSHORE FLOW. THE REST OF THE PANHANDLE WILL SEE A CHANCE
OF LIGHT RAIN OVER THE NORTHERN HALF WITH A WEAK SHORTWAVE MOVING
OVER THE NORTHERN AREAS LATE IN THE DAY. THE SOUTHERN AREAS WILL
SEE A FAIRLY DRY DAY AND MAY SEE SOME BREAKS IN THE CLOUD COVER
AS THEY WILL FEEL THE AFFECT OF THE UPPER HIGH MORE.  ABJ

.LONG RANGE...
FORECAST PROBLEM IS TO CONSIDER STORM FORCE ON MARINE ZONES 51
AND 52 LATER ON THU. MODELS IN SIGNIFICANT DISAGREEMENT AS TO
WAVE IN CENTRAL GULF ON THU...BUT BOTH NCEP SOLUTIONS HAVE A
PRETTY STRONG SFC PRESSURE GRADIENT IN THE NORTH GULF WITH
EUROPEAN MODELS WEAKER. USED 12Z UKMET PRESSURE AS COMPROMISE.
12Z GFS ENSEMBLE SPREAD HUGE. ONLY MODERATE CONFIDENCE DAY 3 THEN
LOW CONFIDENCE DAYS 4 AND BEYOND.   JC

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...NONE
MARINE...SCA...ENTIRE COASTAL WATERS...PKZ13-21-22-33-35-36